A magnetic recording medium used for audio recording, video recording or for computers has recently been required to be highly sensitive. The magnetic recording medium can be made highly sensitive by improving recording systems of a deck for magnetic recording and replaying and a magnetic recording medium, as well as a magnetic recording medium itself, whereby a high quality image, a high quality sound and a high density recording can be realized.
A magnetic recording medium can be highly sensitive also by smoothing the surface of the magnetic recording medium. But the smoothing undesirably causes deterioration of running durability and properties of uniformly winding up tapes; increase of friction coefficient; and generation of wear of the magnetic layer and a backing layer thereof. As a result, drop out and output fluctuation increase.
The present inventors performed extensive research directed to developing a backing layer to remove the above defects and as a result it was found that remarkable improvements can be made by using a certain kind of a resin for a binder, two kinds of carbon black having a certain particle size and, if necessary, a talc in a certain mixing ratio in a backing layer. Thus, the present invention was obtained.